From: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Date: Thu, 26 Feb 2026 15:34:55 +0000 (-0500)
Subject: drm/amdgpu: In GFX12.1 CU is same as WGP
X-Git-Tag: v7.2-rc1~141^2~24^2~104
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=1e5d97a5c59a2f2be97cc3cde0e2fe18781493da;p=thirdparty%2Fkernel%2Flinux.git

drm/amdgpu: In GFX12.1 CU is same as WGP

Fix this for current ip discovery table.

v2: Move the change to gfx12 file
v3: Change only for the current version of ip discovery table
v4: Squash in build fixes

Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
index b0dfbd672b766..57cff29b30024 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
@@ -3422,3 +3422,28 @@ int amdgpu_discovery_set_ip_blocks(struct amdgpu_device *adev)
 	return 0;
 }
 
+int amdgpu_discovery_get_gc_major_minor_version(struct amdgpu_device *adev,
+						uint16_t *major, uint16_t *minor)
+{
+	uint8_t *discovery_bin = adev->discovery.bin;
+	struct table_info *info;
+	union gc_info *gc_info;
+	u16 offset;
+
+	if (!discovery_bin)
+		return -EINVAL;
+	if (amdgpu_discovery_get_table_info(adev, &info, GC))
+		return -EINVAL;
+
+	offset = le16_to_cpu(info->offset);
+	if (!offset)
+		return -EINVAL;
+
+	gc_info = (union gc_info *)(discovery_bin + offset);
+
+	if (major)
+		*major = le16_to_cpu(gc_info->v1.header.version_major);
+	if (minor)
+		*minor = le16_to_cpu(gc_info->v1.header.version_minor);
+	return 0;
+}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.h
index 0ff1a7923eedf..e0010f6a3eda5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.h
@@ -48,6 +48,8 @@ int amdgpu_discovery_get_nps_info(struct amdgpu_device *adev,
 				  uint32_t *nps_type,
 				  struct amdgpu_gmc_memrange *ranges,
 				  int *range_cnt, bool refresh);
+int amdgpu_discovery_get_gc_major_minor_version(struct amdgpu_device *adev,
+						uint16_t *major, uint16_t *minor);
 
 void amdgpu_discovery_dump(struct amdgpu_device *adev, struct drm_printer *p);
 
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v12_1.c b/drivers/gpu/drm/amd/amdgpu/gfx_v12_1.c
index f4089ab108474..6872ce3f3ebbe 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v12_1.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v12_1.c
@@ -1142,6 +1142,7 @@ static int gfx_v12_1_rlc_backdoor_autoload_enable(struct amdgpu_device *adev)
 
 static int gfx_v12_1_sw_init(struct amdgpu_ip_block *ip_block)
 {
+	uint16_t major_ver, minor_ver;
 	int i, j, k, r, ring_id = 0;
 	unsigned num_compute_rings;
 	int xcc_id, num_xcc;
@@ -1152,6 +1153,15 @@ static int gfx_v12_1_sw_init(struct amdgpu_ip_block *ip_block)
 		adev->gfx.mec.num_mec = 1;
 		adev->gfx.mec.num_pipe_per_mec = 4;
 		adev->gfx.mec.num_queue_per_pipe = 8;
+
+		if (!amdgpu_discovery_get_gc_major_minor_version(
+			    adev, &major_ver, &minor_ver)) {
+			if (major_ver == 1 && minor_ver == 3) {
+				adev->gfx.config.max_cu_per_sh /= 2;
+				dev_dbg(adev->dev, "Halving max_cu_per_sh for GC Discovery table v1:3 %d\n",
+					adev->gfx.config.max_cu_per_sh);
+			}
+		}
 		break;
 	default:
 		adev->gfx.mec.num_mec = 2;